Turbomachines are exposed to significant operational stresses from heat and rotational forces. As turbomachines increase their outputs, the size and required properties of the turbomachine's rotor shaft increase. Forged/hardened steel (e.g., a NiCrMoV alloy) is the material of choice for rotor shafts, and rotor shafts are typically machined out of a steel forging. The material of the rotor shaft is usually quenched-tempered high-strength low-alloy steel with critical fatigue properties. The NiCrMoV alloy currently used for these rotor shafts employ nickel, chromium, and molybdenum to provide a desirable hardenability of the alloy. Although NiCrMoV has performed well in smaller rotor shafts, it does not provide desired hardenability and fracture appearance transition temperature (FATT) in larger rotor shafts. With the trend toward larger gas turbines and bigger compressor rotor components such as wheels and forward stub shafts, the current materials such as NiCrMoV steel are falling short of the desired properties, in particular deep-seated impact toughness properties. The large cross-sections of these parts make it challenging for manufacturers to meet the FATT requirements, particularly in deep seated locations where the cooling rate is the slowest during quench and temper heat treatment processes.